V_2O_3碳热还原法制备VC过程的研究

Preparation Process of Vanadium Carbide by Carbonthermal Reduction of V_2O_3

以V2O3粉末和石墨粉为原料在氩气气氛下制得VC。用红外气体分析器测定反应过程中产生的CO,得到V2O3碳化过程的动力学方程,同时对不同温度下的产物进行物相分析。结果表明,V2O3碳热还原反应在1 420～1 630 K之间反应较快,在1 520K下恒温2 h反应过程中产生的CO含量较少;随反应温度的不同,产物VC的晶格常数也随之发生变化,且产物中有未反应的钒氧化物。温度在1 420～1 630 K之间反应活化能和指前因子分别为E=411.04 kJ·mol-1和A=8.4×1010 s-1。

Vanadium carbide was prepared in argon atmosphere using V2O3 and graphite powder as raw materials.The concentration of CO produced in the reaction was measured by infrared gas analyzer,and the kinetic equation of carbonization process was obtained.X-ray diffraction（XRD） was applied to analyze the phase compositions of the products at different temperature.Results show that carbonthermal reduction reactions of V2O3 are fast between 1 420 ~ 1 630 K.Low CO concentration appears while the temperature is thermostatic at 1 520 K for 2 h.The lattice constants of the products are different at different temperatures and unreacted vanadium oxide appears in the products.Activation energy（E） and frequency factor（A） are 411.04 kJ·mol-1 and 8.4×1010 s-1 respectively at the temperature range of 1 420 ~ 1 630 K.